Promoting reflection on bioethics and research ethics issues in Sub-Saharan Africa

Monday, September 17, 2012

Chronic kidney disease: a whodunit

There is a serious disease increasingly affecting the poor in South Asia that is shrouded in mystery. Despite it being discovered some twenty years ago, it is unclear how to prevent it, how to treat it, and most importantly, what causes it. Even its name is more suggestive than descriptive: chronic kidney disease of unknown etiology or CKDu. Unlike ordinary CKD, which affects older males and females and is associated with in developed countries with diabetes, obesity and hypertension, CKDu primarily affects males of working age, particularly farmer workers. CKDu has also been reported to be epidemic in some Central American countries, with the bulk of incidence involving sugarcane field workers. What is happening?

The answer seems to be: no one really knows yet. The World Health Organization and the Sri Lankan Ministry of Health produced a study that suggests the cause of CKDu may be due to chronic, low-level exposure of workers to cadmium and arsenic that can be found in pesticides and fertilizers. But the Sri Lankan government appears reluctant to widely publicize the report in order to inform both farm workers and food consumers, who also may be at risk. This reluctance has raised suspicions among observers: is the Sri Lankan government unwilling or unable to regulate agro-business, particularly the corporations that sell pesticides and fertilizers in the country. Is it because the government itself partly to blame for the rising incidence of CKDu, due to it subsidizing the costs of the fertilizers and pesticides that farmers then tend to overuse in their fields? Public Radio International (PRI's The World) has a report on the issue from a number of different angles. It goes without saying that because the epidemic is serious and because there is no clarity about the etiology of disease, speculation and conspiracy theories abound.

Whatever the causes and the responsibility, the current consequences for farmers and their communities is clear, and clearly bad. Those with CKDu find themselves unable to work and having to seek treatments (like dialysis) they can barely -- or not -- afford. Research, surveillance, policy-making and political will have to come together, and quickly, to prevent laborers in a crucial industry in developing countries from becoming seriously ill and dying.

Chronic kidney disease slowly gets worse over time. In the early stages, there may be no symptoms. The loss of function usually takes months or years to occur. It may be so slow that symptoms do not appear until kidney function is less than one-tenth of normal.